A wiring structure for an electro-optical composite cable and a ferrule is disclosed in, for example, Patent Document 1 to Patent Document 3. The wiring structures disclosed in them are as follows. First, a tubular member integrally formed with (or prepared separately from) the ferrule is inserted between an optical fiber strand and a tensile-strength resistant fiber. Next, the ferrule is crimped so that the tensile-strength resistant fiber and an outer jacket are interposed between the ferrule and the tubular member. Thus, the electro-optical composite cable is connected with the ferrule without using an adhesive agent or the like.
A split sleeve (a sleeve having a cut portion) is known as a connection member connected with the ferrule. Techniques which solve a problem of the split sleeve are disclosed in Patent Document 4 to Patent Document 6. Each of the connection members disclosed in them is not provided with the cut portion. The connection member is configured to support the ferrule at three points (surfaces). Patent Document 7 discloses an improved technique of Patent Document 4.
Patent Document 8 discloses one of the examples of connectors and an adaptor wherein each of the connectors is connected with an electro-optical composite cable, and the adaptor connects the connectors with each other. The disclosed connector comprises a conductive ferrule holding an optical fiber included in the electro-optical composite cable while connected with a metal conductive material of the electro-optical composite cable. The adaptor is made of a synthetic resin. A conductive connection member adjusting a position of an axis of the ferrule is formed in the adaptor by insert molding. An electrical connection between the ferrules is carried out as follows. First, each ferrule of two connectors is inserted into the connection member. Then, end surfaces of the ferrules are brought into contact with each other within the connection member.
A technique relating to hot swapping of the electrical connector is disclosed in, for example, Patent Document 9. The disclosed electrical connector uses contacts each of which has a projection length from the connector wherein the projection lengths are different from each other so that a timing of connection can be shifted for every contact. The above-described structure enables the hot swapping.    Patent Document 1: JPA 2004-191397    Patent Document 2: JPA 2006-146084    Patent Document 3: JPA 2006-84788    Patent Document 4: JPA H10-31134    Patent Document 5: JPA S59-204814    Patent Document 6: JPA H5-164941    Patent Document 7: JPA 2006-23420    Patent Document 8: JPA S62-19813    Patent Document 9: JPA H6-5153